High-Accuracy PCR Testing for Respiratory Viruses

Dr. Pallavi Upadhyay • Oct. 30, 2024

This study compared three PCR-based testing platforms for detecting SARS-CoV-2, Influenza A (FluA), Influenza B (FluB), and Respiratory Syncytial Virus (RSV) aiming to support reliable diagnosis of respiratory tract infections, which often present similar symptoms. The study evaluated the performance of HealthTrackRx’s multiplex treatable respiratory virus panel, TrueMark™ SARS-CoV-2, Flu A, Flu B, RSV Select Panel, and the FDA-approved (IVD) platform BioFire® Respiratory 2.1 (RP2.1) Panel.

Results showed 100% agreement across the tests, indicating that HealthTrackRx’s laboratory developed tests (LDTs) performed as accurately as the FDA-approved platform. These findings suggest that HealthTrackRx’s LDTs can be effectively used for accurate, timely diagnosis of respiratory viruses in clinical settings.

Globally, viral Respiratory Tract Infections (VRTIs), particularly Influenza, SARS-CoV-2, and RSV, pose a significant health and economic impact. These viruses lead to substantial illness, hospitalization, and mortalities each year, with the economic burden in the U.S. reaching billions. For example, annual economic impact of influenza infections ranges from $11.2 to $35.4 billion, while the cumulative cost of SARS-CoV-2 has surpassed $5.6 trillion. RSV also poses a considerable threat, particularly to young children and older adults with comorbidities, with hospitalizations costing an estimated $1.3 billion.

After the recent global pandemic, where SARS-COV-2 predominated respiratory tract infections and influenza like-illness (ILI), the 2022-2023 “tripledemic” of Influenza viruses, COVID-19 and RSV, overwhelmed the healthcare system. Global epidemiological trends indicate a pre-pandemic circulation and infection pattern of respiratory syncytial virus (RSV) and influenza A/B viruses which exhibit a significant overlap in circulation. Clinical presentation of these viral infections often demonstrates similar ILI symptoms, presenting a diagnostic challenge in identifying the causal pathogen based on the symptoms alone. Therefore, reliable and timely testing is required to accurately identify the presence of these respiratory pathogens. This study evaluates the performance of the HealthTrackRx’s treatable respiratory virus multiplex PCR panel against other established PCR platforms for detecting these key respiratory viruses.

VRTIs are one of the major global healthcare burdens due to high morbidity and mortality rates, especially among vulnerable patient populations. Thus, accurate detection and surveillance of these viruses are critical, particularly during the winter months when these viruses are known to co-circulate. PCR-based molecular tests, utilized for the detection of VRTI-causing pathogens, have shown to reduce the length of hospitalizations and overall decrease in the healthcare costs, especially during previous outbreaks and recent COVID-19 pandemic. Based on the very good agreement of these three tested assays, we recommend that the HealthTrackRx developed multiplex real-time PCR LDT (Treatable respiratory virus panel) can be employed for the detection of respiratory viruses (for the detection of SARS-CoV-2, FluA, FluB, and RSV) in clinical settings.

For the 200 de-identified respiratory samples (nasopharyngeal and oropharyngeal), the HealthTrackRx developed Treatable Respiratory Virus panel and TrueMark™ SARS-CoV-2, Flu A, Flu B, RSV Select Panel displayed a positive predictive agreement of 100% [95% CI (97.7%, 100%)] and negative predictive agreement of 100% [95% CI (91.9%, 100%)]. The real-time PCR based panels demonstrated comparable cycle threshold (Ct) values for the detected viral targets. For the detection of SARS-CoV-2, Flu A, Flu B, RSV, both HealthTrackRx panels showed an overall agreement of 100% [95% CI (98.1%, 100%)] with the FDA-approved BioFire respiratory panel (RP 2.1).